Panasonic Multisplit

[Debonair Spain]

Hi guys, installed a Panasonic Inverter Multisplit 3 indoor units approx 18 months ago, a problem has arose, the system runs for about 5 mins with no cooling. LED 1 and 3 on outdoor unit is on and this is relating to high discharge pressure. The suction pressure is running at 2 bar and the liquid line pressure is showing 18 bar and yet the indoor units are not showing a fault by the timer light.

Can anyone shed some light.

Thanks

[frank]

From your symptoms, I would say that a high discharge pressure and low suction pressure (starved evaporator) it seems that you may have a slight blockage.

are the expansion valves (eev's) opening correctly? or more likely, it is a common problem before the eev's (blockage) as all of the indoor units are doing the same.

[Debonair Spain]

Hi Frank thanks for your input, yes it does seem to be a blockage of some sort as all units are not cooling and the EEV´s are making quite a noise, not sure if they are closed when trying to cool.

[frank]

You need to use a touch probe thermometer around the outdoor unit piping to locate it if it doesn't run long enough to start frosting or doesn't cause frosting at all.

It will certainly show as a rapid temp drop with the probe though

[monkey spanners]

Is this high pressure or high discharge temperature, 18bar doesn't seem that high for R410A, i think they usually trip around 40bar! (but could be wrong)
If its high discharge temp, it could be short of refrigerant, so i'd be weighing it out to see if it has the correct charge.

[frank]

Good point MS

It's always difficult to pinpoint the cause when you are not working on the system as certain symptoms can look like one thing but end up being something completely different :)

[Debonair Spain]

Hi Frank and MS would you have a high side pressure of 18Bar (Which is not that high, it is almost normal), when you have a suction pressure of low side pressure of 2Bar

[frank]

As MS says, it would be a good idea to check your gas charge first